Quicksilver Elemental can gain the activated abilities of any creature on the battlefield that you can target with its ability, even if you don’t control that creature.

12/1/2004

The granted abilities effectively use “this permanent,” rather than “[that card’s name],” so you treat the abilities as if they were printed on Quicksilver Elemental. For example, you treat an ability that says “Sacrifice a creature: Nantuko Husk gets +2/+2 until end of turn” as “Sacrifice a creature: Quicksilver Elemental gets +2/+2 until end of turn.”

12/1/2004

Quicksilver Elemental has a rather tricky interaction with Leonin Bola. You can actually unattach your opponent’s Bola as part of the cost of activating the Elemental-copied ability.

6/8/2016

Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keywords are activated abilities and will have colons in their reminder text.